Splatter indicator sight for firearms

ABSTRACT

Method of providing a gun sight for a firearm having an accuracy comprising predetermining as a function of the accuracy a region surrounding a point of aim within which a projectile issued from the firearm will strike with a known probability, aiming the firearm at the intended target, and outlining the region about the point of aim with a laser and method for supporting a decision to fire a projectile from a firearm having an accuracy and pointed towards an intended target and an unintended target comprising precalculating as a function of the accuracy a region surrounding a point of aim within which a projectile issued from the firearm will strike with a known probability, aiming the firearm at the intended target, delineating the region about the point of aim with a laser, and not firing when at least a portion of the unintended target is within the region.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 12/352,355, now pending, filed on Jan. 11, 2009, which itselfclaims benefit of U.S. provisional application Ser. No. 61/020,515,filed on Jan. 11, 2008. All documents above are incorporated herein intheir entirety by reference.

FIELD OF THE INVENTION

The present invention relates to a splatter indicator sight forfirearms. More specifically, the present invention is concerned with anindicator device for processing data regarding variables affecting thebullet trajectory and creating a visual map of all of the probable hitzones after the user has aimed the firearm at the target, therebyallowing the user to evaluate the risk of hitting the wrong targetbefore shooting.

BACKGROUND OF THE INVENTION

Firearms, such as handguns (single-shot pistols, revolvers, andsemi-automatic pistols), long guns (rifles, carbines or shotguns) andmachine guns or the like are aimed at their targets with greateraccuracy by using sights. Many sights can be mounted onto firearms, forexample, telescopic sights (or scopes), iron sights, red dot sights, andlaser sights.

Despite these existing sighting systems, aiming errors still occur.Those errors depend to some degree on the skill of shooter, but also thequality and caliber of the firearm and other exterior conditions such asthe range to the target, the movement of the target, the ambient light,and the wind. The aiming error becomes a considerable issue when thefirearm is used by security forces in civilian zones where there existsa risk of hitting an innocent bystander or other friendly by accident.

The prior art reveals processing of data affecting the bullet trajectoryin order to correct the aim or provide warnings to the user (where datareceived from sensors mounted onto the firearm or entered by the user isprocessed and provides for the automatic adjustment of aim,stabilization as well as the display of data related to aiming error)these existing aids focus on perfecting the aim. Potential for errorstill exists, however, and a shot fired might fall within an areasurrounding the point of aim. Therefore, there is a need for a devicethat will clearly and quickly indicate the probable hit zones around theaiming point to let the user better decide whether or not to shoot.

SUMMARY OF THE INVENTION

In order to address the above and other drawbacks there is provided amethod for supporting a decision to fire a projectile from a firearmhaving a firearm accuracy and pointed towards an intended target and anunintended target. The method comprises pre-calculating as a function ofthe firearm accuracy a first region surrounding a point of aim withinwhich a projectile issued from the firearm will strike with a knownprobability, aiming the firearm at the intended target, delineating thefirst region about the point of aim with a laser affixed to the firearm,and not firing when at least a portion of the unintended target iswithin the first region.

There is also provided a method of providing a visible gun sight for afirearm having an accuracy. The method comprises pre-determining as afunction of the firearm accuracy a first region surrounding a point ofaim within which a projectile issued from the firearm will strike with aknown probability, aiming the firearm at the intended target, andoutlining the first region about the point of aim with a laser affixedto the firearm.

Other objects, advantages and features of the present invention willbecome more apparent upon reading of the following non-restrictivedescription of specific embodiments thereof, given by way of exampleonly with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the appended drawings:

FIG. 1 discloses a laser sight mounted on a firearm and used to projectthe risk zone map on the target in accordance with an illustrativeembodiment of the present invention;

FIG. 2A discloses a risk zone map projected on a flat surface by thesplatter indicator sight in accordance with an illustrative embodimentof the present invention;

FIG. 2B discloses the risk zone map of FIG. 2A projected on a target;

FIG. 2C discloses the risk zone map of FIG. 2A projected on a targetlocated in a crowd of innocents or friendlies;

FIG. 3A and FIG. 3B disclose a risk zone map in accordance with a firstalternative embodiment of the present invention;

FIG. 4A and FIG. 4B disclose a risk zone map in accordance with a secondalternative embodiment of the present invention;

FIG. 5A and FIG. 5B disclose a risk zone map in accordance with a thirdalternative embodiment of the present invention;

FIG. 6A and FIG. 6B disclose a risk zone map in accordance with a fourthalternative embodiment of the present invention; and

FIG. 7 is a block diagram of the splatter indicator sight components inaccordance with an illustrative embodiment of the present invention.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention is illustrated in further details by the followingnon-limiting examples.

Referring now to FIG. 1, and in accordance with an illustrativeembodiment of the present invention, a firearm comprising a splatterindicator sight, and generally referred to using the reference numeral10, will now be described. The firearm 10 comprises a splatter indicatorsight 12 comprising a laser (not shown) emitting a laser beam 14co-aligned with the muzzle 16. The indicator sight 12 is illustrativelymounted within the chamber 18 which also houses the recoil spring (notshown). Alternatively, the indicator sight 12 could be positioned on topof a firearm 10 or below the barrel on a dovetail, MIL-STD-1913Picatinny rail or similar mount.

Still referring to FIG. 1, many aiming errors are directly caused by theuser. For example, parallax is created when the user moves in relationto the sight 12. Additionally, normal shaking of the hand holding thefirearm 10 can be amplified when the user finds himself within astressful situation. Also, when a shot is fired, recoil can furtheramplify the movement of the hand holding the firearm 10.

Referring now to FIG. 2A in addition to FIG. 1, in an illustrativeembodiment of the present invention, the laser beam 14 emitted orprojected by the indicator sight 12 forms a pattern 20, or risk zonemap, when projected on a surface located in front of the firearm 10 andsurrounding the point being aimed at 22. The contour(s) 24 defined bythe risk zone map 20 can adopt various shapes according to the values ofthe different data taken into account. In the present illustrativeembodiment the contour(s) 24 are represented by an oval shape since theaiming error will presumably be greater relative to the upper/lower axisA of the firearm 10. The risk zone map 20 defines the limits of the mostprobable hit zones (in other words, a predetermined level of probabilitythat a projectile issued from the firearm will strike within a definedregion) according to calculations which will be described in more detailhereinbelow.

Referring now to FIG. 2B, when the firearm 10 is aimed at a target 26,the risk zone map 20 is projected onto the target 26 surrounding thepoint being aimed at 22. In the context of FIG. 2B, the risk zone map 20indicates that there is less risk of shooting an innocent or otherfriendly as only the target 26 is found within the risk zone map 20.

On the other hand, and referring now to FIG. 2C, the risk of hitting aninnocent or other friendly by accident is increased as, although thepoint being aimed at 22 falls on a target 26, innocents or otherfriendlies as in 28 also fall within the risk zone map 20. Additionally,referring back to FIG. 2A, in a particular embodiment a readablecharacter symbolic of the predetermined level of probability that aprojectile issued from the firearm will strike within a defined regioncan be displayed adjacent the defined region(s).

Referring now to FIG. 3A and FIG. 3B, in a first alternativeillustrative embodiment the risk zone map 20 is characterized by acentral point 30 surrounded by a circle 32 indicating a region withinwhich the risk of accidentally shooting an innocent is high. In thisregard, and as will now be understood by a person of ordinary skill inthe art, the circle 32 is projected as a cone such that the diameter ofthe circle 32 increases with an increase in distance between theindicator sight (reference 12 in FIG. 1) and the target 26.

Referring now to FIG. 4A and FIG. 4B, in a second alternativeillustrative embodiment the risk zone map 20 is characterized by atarget-like series of concentric circles as in 34. The risk ofaccidentally hitting an innocent decreases with an increase in therelative diameter of a given circle as in 34. Each of the increasingcircles as in 34, for example, could represent an incremental increaseof the Minute of Arc (MOA).

Referring now to FIG. 5A and FIG. 5B, in a third alternativeillustrative embodiment the risk zone map 20 is characterized by across-hair comprising a pair of crossing elements as in 36 arranged atright angles to one another.

Referring now to FIG. 6A and FIG. 6B, in a fourth alternativeillustrative embodiment the risk zone map 20 is characterized by across-hair reticule comprising a pair of crossing elements as in 36arranged at right angles to one another and with the addition ofcross-hatch as in 38 on each of the pair of crossing elements as in 36.Illustratively, and similar to that as described above in regards toFIG. 4A and FIG. 4B, the relative distance of the cross-hatch as in 38from the point of crossing 40 of the crossing elements as in 36 couldrepresent a relative increase or decrease in the MOA.

A variety of approaches may be used for generating and projecting therisk zone map 20 on a target 26 using a laser 14.

For example, in a first illustrative embodiment of same, the actuallasing action can be used to set the desired beam divergence. In otherconfigurations a laser will generate a beam with a given divergence(typically on the order of 0.5-10 mrad) and then the desired spreadangle will be set with external collimating optics. Lasing action in thelaser cavity can be controlled to some degree with the configuration ofthe laser cavity, adjusting parameters such as mirror curvature,spacing, selection of location of the beam waist, inter-cavityapertures, bore diameter, etc. Specifically, in semiconductor (diode)lasers, an apparent point source can be generated by ion milling (orsimilar) a convex high reflector mirror into the diode laser's cavity.

In a second illustrative embodiment divergence of the laser can beintroduced using a collimating telescope. In this regard, a single,solid cone of light is generated from a single laser source and aGalilean or Keplerian telescope is placed in the beam to collimate, ordecollimate, the emitted laser beam. These telescopes may use two ormore optics. Adjustment between the separation distance of these twooptics in either telescope (focus) can provide for a change in thedivergence angle of the emitted beams.

In the above two embodiments, it may also be desirable to utilize a beamdiffuser, of which a number of known types exist, to generate a moreuniform beam profile (top hat), prior to adjusting the beam divergence.This provides for much more uniform laser spot illumination assistingvisibility and more carefully defining the edge of the desired spot.

In a third illustrative embodiment a diffuser may be used in conjunctionwith the laser 14 to generate a cone angle. Rather than using atelescope to change the natural divergence of the generated beam, adiffuser may be designed and used to generate a cone of light of thedesired angle. Although “opal glass” or rough surface glass diffusersare common and could potentially be used, a Holographic Optical Element(HOE) diffuser is preferable.

In a fourth illustrative embodiment, HOEs are designed and used to shapelight to precise shapes and patterns as they provide a low cost andoptically efficient means to make complex projection patterns. Inparticular, both binary and diffractive optics, which are closelyrelated, are included here. Employment of a custom pattern/angle HOE orother phase mask may be used for some implementations.

In a fifth illustrative embodiment, rear illumination and subsequentcollimation of a window or mask pattern can be used. This wouldtypically be a glass or plastic window with a pattern applied opaquely,such as chrome on glass, a chemically etched or laser cut stainlesssteel stencil or similar. A lens or lens system is used downstream ofthe window to gather light and collimate to the desired angle ofdivergence. The pattern disc may be somewhat diffuse in nature.

In a sixth illustrative embodiment, the risk zone map 20 is the resultof a vector scan which traces the desired image or pattern using arapidly moving spot. Scanning of simple patterns such as circles can beachieved with a spinning off axis mirror, wedge cut refractive optic orthe like. Complex patterns can be achieve by spinning HOE scanneroptics, or more conventionally with XY galvanometer scanners. The sameresult might also be achieved with MEMs scanning devices such a DLPs,GLVs and related technologies.

In a seventh illustrative embodiment, areas can be delineated with theuse of multiple static spots rather than full vector or filled patterns.This is discussed more below as an additional claim as a way to increasethe image brightness.

The visibility of the laser light on a target is determined by theenergy density at the target location reflected back to the viewer'slocation. Even low power laser light may be quite visible when viewed ata significant distance if it remains in a small spot. However, if theangle of divergence is significant, and/or the spot is large, as it maybe at long distances, practical and/or safe levels of laser light maynot be as visible as would be desirable when the spot spreads to a largediameter. In order to address this problem, one solution is to delineatethe diameter of an imaginary circle or box with two or more individuallow divergence (small diameter) beams to maintain brightness with lowlevels of power. These multiple beams could be generated with multiplelasers, or with discrete optics or HOE, diffractive or binary optics togenerate multiple beams from a single input beam (single laser).

As discussed above, the effect of the offset and/or parallax between thepath of the bullet and the path of the laser light can affect can varyfrom moderate to insignificant depending on the distance from thefirearm to the target. Indeed, if the laser is simply a cone of lightbeing emitted from a device mounted, for example, to the top of thebarrel of the firearm, for example like a riffle scope, there is offsetbetween the origin of the path of the laser light and the path of theprojectile (bullet). If the natural fall of the bullet is not taken intoaccount, both the laser light and the bullet will travel a straightpath, separated by 1-2 inches. If the target is at a significantdistance, this offset is likely insignificant due to the inherent spreadpattern or error in the bullets flight path. However, if the target isclose to the weapon there will be offset, or alternately parallax.

In order to address this problem, the end of the barrel can be fittedwith a mechanism such that the beam or beams are emitted uniformlyaround or directly down the axis of the barrel. This can be achieved ina couple of different manners.

Firstly, a reflector can be placed at some angle at the end of thebarrel (typically 45 degrees). This reflective optic, such as a flatmirror will have a hole in the center to allow the passage of theprojectile, while still allowing reflection of the light in a pathconcentric with the projectile.

Secondly, an optic can be used to collimate the light around the path ofthe projectile which is not a planar (flat) mirror, but may be a concaveoptic such as an off axis parabola. These approaches would also have ahole in the center, through which the projectile can pass.

Thirdly, a diffractive, holographic, binary or phase grating can be usedto shape the light into the desired collimated pattern without a concaveshape/curved surface.

Depending on the use environment, front surface mirrors may be desired.

Alternatively, one beam could be emitted above or below the barrel andone to the right or left of the barrel. In this way, the user imaginesthe intersection of a horizontal and vertical line as the center ofemission, and then uses the location of the two beam spots to constructa square or circle which represents the risk zone map.

Also, for special single use conditions, a pellicle beam splitter can beplaced directly over the end of the barrel at some angle, typically 45degrees. The pellicle beams splitter is made from a very thin opticallyreflective layer of cellulous, mylar or similar material. The thicknessof this material can be just a few microns such that it is an extremelythin weak film which will be pierced with milligrams of force and thusnot affect the projectile, thereby allowing the emitted laser light tobe aligned precisely with the bore of the weapon with zero offset orparallax. It can be noted that the pellicle beam splitter is effectivelya tympanic membrane and will respond to acoustic vibrations (sound),this may limit its use in some situations. Alternately, a solid but verythin glass beam splitter could be used and shatter upon use.

Referring now to FIG. 7, an illustrative embodiment of the electronics42 used to drive the laser beam 14 will now be described. Theelectronics 42 comprises a CPU 44 which receives data from one or moresensors as in 46, processes the data according to a program (not shown)stored in a Read Only Memory (ROM) 48 and/or Random Access Memory (RAM)50 as well as user inputs (also now shown) received via a user interface(I/O) 52 and illustratively stored in the RAM 50. In this regard theuser interface 52 could be provided by one of a number of meansincluding user selectable buttons (not shown), infrared, USB or thelike. The CPU 44 provides control signals to a laser driver 54 whichdrives the laser beam 14 to project the risk zone map (reference 20 inFIG. 1). Additionally, a source of power 56, such as a battery or thelike, is provided to power the electronics 42 and the laser beam 14.Referring back to FIG. 1 in addition to FIG. 7, control of powersupplied by the source of power 56 to the electronics 42 and the laserbeam 14 can be controlled, for example, by slightly depressing thetrigger 58 or through provision of a switch (not shown) or the like.

Still referring to FIG. 7, the sensors as in 46 may comprise one or moreof a variety commercially-available electronic sensors such asaccelerometers or the like. Listed below are examples of data that canbe taken into consideration for calculating the risk zone map 20:

-   -   target data: distance, height, speed;    -   meteorological data: wind direction and speed, temperature,        pressure, humidity;    -   spatial data: movement of firearm (banking, rotation, lateral,        up-down);    -   ammunition data: cartridge info, bullet weight, ballistic        coefficient;    -   weapon data: weapon length (farthest distance to which an        averagely-trained soldier can hit a man-sized target).

Still referring to FIG. 7, one parameter of interest which can be usedas a basis for determining the proportions of the risk zone map 20 isthe maximum effect range. In this regard, firearm manufacturerstypically determine for each firearm a distance at which an averagelytrained soldier using the particular firearm is able to hit a man-sizedtarget (typically 46 cm×91 cm or 18″×36). Some typical values for someknown firearms are provided below:

-   -   M9 9 mm Glock/Berrette 50 m    -   M4 5.56 mm Carbine 200 m

Another parameter of interest (discussed briefly above) and which mayalso be used to determine the proportions of the risk zone map 20 is theMOA. MOA is a unit of angular measurement equal to one sixtieth ( 1/60)of one degree. One (1) MOA is one inch at 100 yards (91 meters). MOA isoften used when characterizing the accuracy of rifles and indicatesthat, under ideal conditions, the firearm in question is capable ofrepeatedly producing a group of shots whose center points(center-to-center) fit within a circle, the diameter of which can besubtended by that amount of arc.

Although the present invention has been described hereinabove by way ofspecific embodiments thereof, it can be modified, without departing fromthe spirit and nature of the subject invention as defined in theappended claims.

1. A method for supporting a decision to fire a projectile from afirearm having a firearm accuracy and pointed towards an intended targetand an unintended target, the method comprising: pre-calculating as afunction of the firearm accuracy a first region surrounding a point ofaim within which a projectile issued from the firearm will strike with aknown probability; aiming the firearm at the intended target;delineating said first region about the point of aim with a laseraffixed to the firearm; and not firing when at least a portion of theunintended target is within said first region.
 2. The method of claim 1;wherein said delineating comprises outlining said first region with saidlaser.
 3. The method of claim 1; wherein said region is circular.
 4. Themethod of claim 1; wherein said laser emits light in a visible spectrum.5. The method of claim 1, further comprising displaying a reticule aboutthe point of aim using said laser.
 6. The method of claim 5, whereinsaid reticule comprises a pair of crosshairs, each of said crosshairsfurther comprising a pair of cross hatches.
 7. The method of claim 1,wherein the firearm has an accuracy rated as units of Minute of Arc(MOA) and further wherein said first region is a circle whose radius issubtended by said units of MOA.
 8. The method of claim 1, wherein saidprojected risk zone map comprises a ring defining said first region. 9.The method of claim 1, wherein said delineated region comprises an ovalring.
 10. The method of claim 1, further comprising pre-calculating asecond region within which a projectile issued from the firearm willstrike with a second predetermined probability and delineating saidsecond region about the point of aim with said laser.
 11. The method ofclaim 10, wherein the firearm has an accuracy rated as one Minute of Arc(MOA) and further wherein said first region is a circle whose radius issubtended by one (1) MOA and said second region is a circle whose radiusis subtended by two (2) MOA.
 12. The method of claim 1, wherein saidlaser further projects a readable character symbolic of said firstpre-calculated probability adjacent said first region.
 13. The method ofclaim 1, wherein said first region is pre-calculated based on aparameter selected from a group of parameters consisting of MOA, targetdata, meteorological data, spatial data, ammunition data, weapon dataand combinations thereof.
 14. The method of claim 1, wherein the firearmhas a maximum effective range and wherein said region delineated by saidlaser is substantially the same size as a man's head and torso when saidfirst region is delineated on a surface located at said maximumeffective range from the fire arm.
 15. The method of claim 14, whereinsaid first region measures 18 inches×36 inches when said first region isdelineated on a surface located at said maximum effective range from thefire arm.
 16. A method of providing a visible gun sight for a firearmhaving an accuracy comprising: pre-determining as a function of thefirearm accuracy a first region surrounding a point of aim within whicha projectile issued from the firearm will strike with a knownprobability; aiming the firearm at the intended target; and outliningsaid first region about the point of aim with a laser affixed to thefirearm.